Why did you change default.asp? Did you replace it with something else? Did you install it in your root web directory?
If that is the case, you should have put the forums in their own directory, and then have your other default.asp page in the root web directory.
On my website, for example, I have http://www.caribbeanchoice.com/default.asp as the website home page, but http://www.caribbeanchoice.com/forums/default.asp as my forums home page.
The forums in are in the /forums/ folder by the way.
That way they don't conflict with each other.
Edited by wistex